Contents

Introduction

The MusicBrainz Next Generation Schema (NGS) is the culmination of five years of planning and two years of active development. It takes MusicBrainz from a "will this work?" open source project aimed at identifying Audio CDs and solidly moves it towards being a comprehensive music encyclopedia.

Releases support packaging and can be be attributed to multiple labels.

If a recording appears on an Album release and a Compilation release it can have the same MBID.

Releases model changes

NGS brings numerous changes to the MusicBrainz "release model".

Previously, a release represented a single disc, it contained a list of tracks, and it could have multiple release events in the case where that disc has been released multiple times, e.g. an album might have been released in the UK, Germany, and the US, all with different release information (country/barcode/label/etc.). Additionally, the previous release model doesn't recognize that the same track may have been issued on different albums. The challenge here is that MusicBrainz' concept of a release ends up trying to represent several different "real world" concepts; it represents: the album the consumer purchased, the physical disc(s) (aka medium) that the audio was contained on, and the specific tracklist the medium contains.

Release

With NGS the release model has been vastly improved upon. A release now represents the specific product a consumer might purchase, e.g. you walk into a store and purchase an album, that album - and all its information and contents - is represented on MusicBrainz as one release. Information that was previously stored in a release event will now be stored at the release-level, effectively making each pre-NGS release event a separate NGS release, complete with its own MBID.

Medium

To remedy the previous problem of having a separate release for each disc, the concept of a medium has been introduced into the NGS release model. A release now contains one or more mediums.

The easiest way to think about a medium is that it represents the actual physical medium the audio content is stored upon. Mediums are what was previously known in the release event as a release format, i.e. CD, DVD, vinyl, cassette, etc.

Tracklist

With the introduction of mediums, we have also introduced tracklists. Sometimes in the real world the exact same tracklist is featured on many different releases, e.g. an album might be released in different countries with the same tracklist, a single may be released on CD and vinyl, or a boxset compilation might consist of previously released material. A tracklist is a bridge between a medium and the tracks it contains, this allows the same tracklist to appear on many different mediums.

Recording

Additionally, the tracks themselves are often released on multiple albums, e.g. it is fairly common to have different tracklists depending on the region an album is released in, but there are usually common tracks between the various tracklists. To recognize that these common tracks are indeed the same, each track on a tracklist is linked to one, recording, however, each recording may be linked to multiple tracks.

A MusicBrainz recording is what the real world might call a track. It is a separate entity from a release and has its own MBID.

Works

Works represent the musical concept of a Work. A composition is a Work and a Recording is the performance of that work fixed in some medium. Composers such a Johann Sebastian Bach never recorded any music in their lifetimes since the technology did not exist, but they created a vast number of musical works. After more cleanup we hope to not have classical composer appear as recording artists any longer.

Missing Features

Even though we've worked on this release for two years, there were a number of things that we pushed off into a future release in an effort to get this release out. These features include:

Search Changes

Incremental update of the indexes (this will be deployed some times after NGS release). This means you won't have to wait 6 hours to find your newly added artist in search results.

Web Service Changes

With this release we no longer support the old RDF web service from 2001!

We have created a backward compatible web service (available at /ws/1). However, this web service is provided for compatibility only and is already deprecated!

We have also created a version 2 web service (at /ws/2) that exposes all of the new features of MusicBrainz NGS -- if you have an application that uses the old version 1 web service, please update your application to use the new web service as soon as possible.

Detailed bug list

For a complete history of the vast number of bugs opened and fixed for this release: